For those of us with smart trainers (Kickr in my case), it would be great if Zwift could control the Kickr for elevation / speed / etc., but record power from my Quarq Riken. That way my workouts on Zwift would more closely match my outdoor workouts.
Agreed. Trainer Road has this functionality now. Better yet will be when Wahoo releases the software (and Zwift and TR integrate the feature) that will allow the Kickr to actually follow your Quark (and any other power meter) instead of its internal power meter.
So…are you saying that you power reading from the kickr are that much different than your poer meter reading of the quarq?
I have read that some people say that after a Kickr gets hot it gets inaccurate by 15-30 watts. 
Bill,
The totally unscientific answer is that it appears that my Quarq diverges from the Kickr during rapid (either higher or lower) changes in power. This is an observation done looking at my Garmin 800 & the displayed power.
I haven’t done any “comprehensive” testing to see if this anecdotal difference ends up making any real difference over the course of a ride.